Fraction of objects classified as point sources in single-epoch SDSS photometry that are indeed point sources according to the Bayesian star–galaxy classification algorithm (Scranton et al. 2002). At the limit of our survey, contamination from galaxies may be as high as ~15%. Brighter than i ~ 20, contamination should be lower than ~5% indicated here, since this plot uses a rather strict cut on galaxy probability that is more appropriate at faint magnitudes than bright.